In communication networks, there are relay apparatuses that execute high-speed data transmission based on communication standards such as Ethernet (registered trademark) and the like. Such relay apparatuses are also called switches or the like. Particularly, in a chassis-type relay apparatus, a plurality of cards corresponding to the functions is connected inside a chassis by being attached thereto. Examples of such cards include a line card that executes data transmission corresponding to a communication standard such as Ethernet as an external interface and a switch fabric card that switches data transmission between ports of a line card. Each of such cards may have a redundant configuration that is multiplexed by a plurality of cards.
As an example of the related art relating to the relay apparatus, there is Japanese Patent Application Laid-Open Publication No. 2003-234757 (Patent Document 1). In Patent Document 1, it has been described to execute switching between a currently-used switch fabric and a preliminary switch fabric, which are duplexed, without any data loss under the control of one controller.